Portable storage device



FIG. 1 is a perspective view of a portable storage device showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line showings of the ports in FIG. 7 are included for the purpose of illustrating portions of the portable storage device and form no part of the claimed design. 

CLAIM The ornamental design for a portable storage device, as shown and described. 